Belt Driven Alternator and Starter with a Series Magnetized Synchronous Machine Drive

Abstract: Electric Hybrid Vehicles, EHV, are under development to provide lower fuel
consumption levels and minimize the environmental pollution compared to
pure Internal Combustion Engine, ICE, driven vehicles. The EHV is more
complex and thus carry many more extra parts than the pure ICE based
vehicle. Competing against the pure ICE vehicle in the sense of nonexpensive
mass production is hard.
This thesis is a result of a research project with the goal to develop a complete
Belt driven Alternator and Starter, BAS, system for a Stop&Go functionality
as a cost-effective hybrid vehicle solution. BAS is based on a Series
Magnetized Synchronous Machine, SMSM, which as an adjustable-speed
drive system comprises power electronics but excludes permanent magnets.
BAS is a rather old concept. It merges two functions, an electric starting
motor and an generator, into one single electric machine. It thereby makes
the total system lighter and smaller. Furthermore, it facilitates technology
leaps on the road towards mass production of electric hybrid vehicles.
The developed BAS system is suitable for a midrange passenger vehicle. The
Stop&Go functionality provides an ICE turn-off at each vehicle stop. The
SMSM is, in addition to generating electricity and starting the ICE, intended
to support the ICE with an additional torque when it is assumed beneficial in
the sense of reaching low fuel consumption.
Topics in the field of power electronics and control of the SMSM that are
covered in this thesis are:
• Simulations on vehicle basis are performed for optimizing the rated
power of the electric machine and its power electronics in the sense
of low fuel consumption.
• The Series Magnetized Synchronous Machine, SMSM, and the
theory lying behind it are presented. The SMSM is carefully
investigated both magnetically and electrically.
• A simulation model for the SMSM is derived based on the
theoretical model that describes the SMSM.
• Based on the theoretical model of the SMSM, dedicated current
controllers are derived. Other types, as standard PI controllers and a
so-called field voltage vector feed forward controller are investigated
and simulated for control of the SMSM.
• The SMSM is tested in laboratory environment for confirming the
behaviour of the derived model of the adjustable-speed drive system
including its power electronics.